Purge task
P(URGE) T(ASK) = (TDWS)nnn
The PURGE command is used to terminate a tape or disk reader task, a writer task or a scheduler task in the DB2 Manager control region. All outstanding requests in the task queue will be allowed to complete normally before task termination.
The command may be abbreviated to a single 'P'. The TASK parameter may be abbreviated to a single 'T'. The value 'nnn' must be numeric and should be preceded by the character ‘T’ for tape reader tasks, ‘D’ for disk reader tasks, ‘W’ for writer tasks and ‘S’ for scheduler tasks. If this character is omitted, a default value of ‘T’ will be used. The task identifier entered here must correspond to a valid reader task number, as displayed by the status summary command.
For waiting tasks (status = WAIT), the purge request will be executed immediately. The identified task will be terminated, and will no longer be available for object recall processing. It will appear with a type of TERM in subsequent status display requests. Any tape allocation held by a purged tape reader or writer task will be released - this will cause the allocated tape to be rewound and dismounted, and the tape drive to be freed by DB2 Manager.
For busy tasks (status=BUSY), a shutdown request will be added to the task queue. This will allow requests which were outstanding at the time the purge command was entered to be completed as normal. The task will then be terminated, and will no longer be available for processing. It will appear with a type of TERM in subsequent status display requests. For tape reader tasks, the tape being processed by the identified task will be released, whether it would have normally been retained on the tape drive after use or not.
Requests to purge a busy task for which a purge request has already been queued will be rejected.
When a task is purged, the current value of the MAXTRDR, MAXDRDR, MAXTWTR or MAXSCHED parameters is automatically decremented by 1, depending on the type of task being purged.
Example:
F LCDDB2,D
OTD20062 Maxtrdr=003 Maxdrdr=004 Maxtwtr=004 Maxsched=004 Maxqlen=100 OTD20062 Retaintape=0001 Tapewait=0004 Objsize=00100
OTD20062 Readtimeout=0005 Writetimeout=0005
OTD20062 Scheduler: Queue is unlocked; Queue length=000
OTD20063 Task T001: Status=TERM Qlen=000
OTD20063 Task T002: Status=WAIT Qlen=000
OTD20063 Task T003: Status=WAIT Qlen=000
OTD20063 Task T004: Status=WAIT Qlen=000
OTD20063 Task D001: Status=WAIT Qlen=000
OTD20063 Task D002: Status=WAIT Qlen=000
DB2 Manager User Guide | 57 |
StorageTek Proprietary |
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